My wife and I recently remodeled our kitchen. We had an electrician install a couple 3-way switches and a 4-way switch.
Unfortunately, he screwed up - when we installed the lights, they wouldn’t work. And unfortunately, his cell phone is “temporarily out of service”.
Fortunately, having learned what SPDT and DPDT switches are at age 10 or so from model railroading, I was able to fix the problem myself! (my wife now thinks I’m pretty smart! - she was quite impressed!)
She always thought you were pretty smart or she wouldn’t have married you. She just slipped up and let you know is all. 
almost 40 years ago when i was an electricians helper i wired up a room with two 3ways and a 4way switch. it didnt work and i checked out the wiring and couldn’t find the problem. well the wiring was right but the 4 way switch was an externally crossed type that i don’t think are made anymore. even the electrician couldn’t figure it out.
I still enjoy the joys of DC wiring…Like you found out,one never knows when some basic wiring skills will come in handy that we have learned in the hobby.[:D][tup]